1. Field of the Invention
The present invention relates, in general, to an apparatus for and a method of installing segmented concrete pilings before a building foundation is installed.
2. Background Art
Pre-cast concrete piles have been in use for the purpose of supporting and/or leveling existing structures for a number of years. These piles are vertically stacked one upon another and driven into the soil to a point of refusal at which a load bearing capacity may be obtained. These segmented piles, installed properly, provide greater support than a shallow method of underpinning. However, there are problems with the existing art.
In unstable soils, there is great potential for upward, downward, and lateral movement. These factors affect the integrity of the pile, as existing segmented piles have no, or very little, lateral support to prevent separation of the piles thus causing misalignment, separation of the pile, and loss of support.
Another important factor with segmented piling systems is proper alignment during installation. With no or very little lateral support between segmented piles using existing procedures, it is difficult to insure proper alignment and prevention of lateral movement during and after installation.
Knight, U.S. Pat. No. 5,288,175, issued Feb. 22, 1994, discloses a continuously reinforced segmental precast concrete underpinning pile system including a plurality of precast concrete piles and a high strength wire strand joining each of the piles.
Willcox, U.S. Pat. No. 5,505,561, issued Apr. 9, 1996, discloses a self-piloting compressible piling system including a plurality of pre-formed pile sections having bores therethrough and adapted to be arranged in end-to-end relation such that the bores are concentrically collinear, an auger plate positioned beneath the lowest of the pile sections, and a tension-bearing cable attached to the auger plate and extending through the bores of the pile sections to load the pile sections and auger plate in compression.
The known prior art has addressed only the repair of existing foundations due to shrinking of expansive soil, etc., and the resulting lack of structural support. That known prior art has relied on the weight of the existing structure to push against in order to press the pilings into the soil under the structure.
Nothing in the known prior art, either singly or in combination, discloses or suggests the present invention.